chrysotile n : a gray or green fibrous mineral; an important source of commercial asbestos
Chrysotile or white asbestos is the most commonly encountered form of asbestos, accounting for approximately 95% of the asbestos in place in the United States and a similar proportion in other countries. It is a soft, fibrous silicate mineral in the serpentine group of phyllosilicates: as such, it is distinct from other asbestiform minerals in the amphibole group. Its idealized chemical formula is Mg(SiO)(OH), in which some of the magnesium ions may be substituted by iron or other cations. Substitution of the hydroxide ions for fluoride, oxide or chloride is also known, but rarer. These are very difficult to distinguish in hand specimens, and polarized light microscopy
Clinochrysotile is the commonest of the three forms, found notably at Asbestos, Quebec, Canada. Its two measurable refractive indices tend to be lower than those of the other two forms. The orthorhombic paratypes may be distinguished by the fact that, for orthochrysotile, the higher of the two observable refractive indices is measured parallel to the long axis of the fibres (as for clinochrysotile); whereas for parachrysotile the higher refractive index is measured perpendicular to the long axis of the fibres.
Physical and chemical propertiesBulk chrysotile, whose hardness is about the same as that of a human fingernail, is easily crumbled to fibres that are, in fact, bundles of fibrils. Naturally-occurring fibre bundles range in length from several millimetres to more than ten centimetres, and by the U.S. Department of Health and Human Services.
- Mindat clinochrysotile
- Mindat orthochrysotile
- Mindat parachrysotile
- "Asbestos-containing Floor Tile and Mastic Abatement: Is there Enough Exposure to Cause Asbestos-related Disease?"
- Deer William Alexander, Howie Robert Andrew, Zussman Jack, An Introduction to the rock-forming minerals, ISBN 0-582-30094-0, OCLC 183009096 pp. 344-352, 1992
- Ledoux, RL (ed), Short course in mineralogical techniques of asbestos determination, Mineralogical Association of Canada, pp. 35-73, 185, 1979.
- http://www.microlabgallery.com/ChrysotileFile.aspx Photomicrographs of parachrysotile and clinochrysotile
- Nolan, RP, Langer AM, Ross M, Wicks FJ, Martin RF (eds), "The health effects of chrysotile asbestos", The Canadian Mineralogist, Special Publication 5, 2001.
chrysotile in Catalan: Crisòtil
chrysotile in Spanish: Crisotilo
chrysotile in French: Chrysotile
chrysotile in Dutch: Chrysotiel
chrysotile in Polish: Chryzotyl
chrysotile in Portuguese: Crisótilo
chrysotile in Slovak: Chryzotil